JP2010131879A - Printing plate and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing method capable of forming accurately an alignment mark, and capable of attaining highly precise alignment to allow precise positioning. <P>SOLUTION: This printing method executes printing by a process for forming a predried ink film onto an ink-separable film sheet, a process for forming an ink film pattern having a reference alignment mark and a pattern of an ink bank surrounding four sides thereof, on the film sheet, by removing an unnecessary portion of the predried ink film by a printing plate, and a process for transferring the ink film pattern to a base material to be printed, to form a printing pattern, by pressing the ink film pattern of the film sheet onto the base material to be printed, to be pressurized from a film sheet side by a transfer roller. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printing method for continuously forming a high-definition pattern on a flexible substrate to be printed such as a long plastic film.

  Conventionally, an ink film pattern is formed by primary transfer on a roll-to-roll continuous sheet film, and further, the ink film pattern formed by primary transfer is secondarily transferred to a substrate to be printed. A reverse printing technique for printing a printing pattern of an ink film on a printing substrate is known.

  For example, an ink thin film is applied to a sheet film by slit coating or the like, and a relief printing plate having a pattern to be formed is pressed against the ink thin film, and the ink film is transferred to the convex portion of the relief printing by primary transfer to transfer the ink thin film to the sheet film. By forming a film pattern and bringing the surface of the sheet film on which the ink film pattern is formed into contact with the surface of the substrate to be printed, the ink film pattern is secondarily transferred to the substrate to be printed, A printing pattern of an ink film with a pattern pattern is printed on the surface of the substrate to be printed.

  Such a printing technique has the following problems. First, when performing secondary transfer, the printing substrate surface and the printing surface of the sheet film are preferably parallel, and if the printing surface of the sheet film hangs down due to gravity, accurate alignment with the printing substrate is difficult. It becomes. In addition, if there is a difference between the tension applied to the sheet film during the primary transfer and the tension during the secondary transfer, the ink film pattern placed on the sheet film is deformed by the shrinkage of the sheet film, and the substrate is printed. The printed pattern of the ink film to be transferred is shifted, and even if accurate alignment with the substrate to be printed is realized, the shift of the pattern is not eliminated. Further, in order to apply a transfer pressure at the time of secondary transfer, a method of performing secondary transfer while moving the transfer roller in a certain direction is generally used, and transfer unevenness due to stress of movement of the transfer roller is likely to occur.

  In order to solve such a problem, Patent Document 1 discloses a technique for controlling the tension of a sheet film fed from an original fabric roll by arranging a take-up roll and a tension roll in the middle thereof.

  However, even if such tension control is performed, it is difficult to adjust a certain tension, and it is difficult to stabilize the position of multicolor overlay printing. For this reason, even if stable tension adjustment is realized without dividing the sheet film in the middle, high-precision alignment printing cannot be performed unless a correct alignment mark without transfer unevenness is formed.

The known literature is described below.
JP 2000-246868 A

  In the alignment mark formation for alignment by printing, even if the alignment mark for alignment is accurately created on the printing plate, it may not be correctly transferred depending on the printing situation. In other words, in the alignment mark formation method by reversal printing, the transferability of the alignment mark differs significantly depending on conditions such as the ink film thickness and transfer pressure, and the alignment mark that is originally the reference is deformed and printed, so that the alignment is correct. There is a problem that cannot be done.

  Therefore, an object of the present invention is to obtain a printing method in which an alignment mark is accurately formed, high-precision alignment is achieved, and high-precision positioning is performed in reverse printing using a sheet-like blanket plate.

  In order to solve the above-described problems, the present invention provides a printing plate used in a printing apparatus that performs reverse printing, and includes a concave pattern corresponding to a reference alignment mark pattern and four sides of the reference alignment mark. The printing plate is characterized in that a concave pattern corresponding to a pattern of an ink bank having a size of twice or more the diameter is formed.

  Further, the present invention provides a step of forming a pre-dried ink film on a film sheet having ink releasability, and then removing unnecessary portions of the pre-dried ink film with a printing plate so as to perform reference alignment on the film sheet. A step of forming an ink film pattern having a mark and a pattern of an ink bank surrounding the mark, and pressing the ink film pattern of the film sheet against a substrate to be printed and pressurizing with a transfer roller from the film sheet side It is a printing method characterized by having the process of transferring an ink film pattern to the said to-be-printed base material, and forming a printing pattern.

  In the present invention, alignment marks for alignment by printing are formed with a stable alignment mark even if the conditions such as ink film thickness and transfer pressure are different. It ensures transferability and enables correct alignment by correctly transferring the reference alignment mark.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIGS. The present invention uses the printing apparatus shown in FIG. 2 to form an ink film pattern on the surface of the film sheet 6 and pressurizes it with a transfer roller 9 to form the surface of the substrate 7 to be printed in the form of a film or plate. This is a method in which the film sheet 6 and the substrate to be printed 7 can be correctly positioned when transferring to the sheet.

  FIG. 1A shows the shapes of the reference alignment mark 1 and the alignment mark 2 that are correctly transferred from the film sheet 6 to the printing substrate 7 according to the present invention. The reference alignment mark 1 is transferred and printed in advance on the substrate 7 to be printed by the printing apparatus. Next, the printing apparatus aligns the alignment mark 2 of the film sheet 6 with the center position of the reference alignment mark 1 of the substrate 7 to be printed, and moves the ink film from the film sheet 6 to the substrate 7 to be printed. Transfer and print the pattern.

  This transfer printing method will be described next. Here, the case where a pattern pattern is transcribe | transferred from the film sheet 6 of a sheet-like transparent film to the to-be-printed base material 7 of a sheet-like transparent film is demonstrated. First, an ink liquid film is formed on the film sheet 6 having ink peelability at the coating unit 21 of the printing apparatus of FIG. That is, the ink liquid film is applied to the entire printing effective surface of the film sheet 6 that is an offset blanket. Then, the ink liquid film is pre-dried to form a pre-dried ink film. Next, an unnecessary pre-dried ink film on the film sheet 6 is removed by the printing plate 22 in the pattern removing unit of the printing apparatus, and a desired ink film pattern is formed on the film sheet 6. The printing plate 22 has an intaglio for reversal printing that removes ink that becomes a non-image area, that is, the resin within the region of the resin film layer having a thickness equal to the desired plate depth formed on the base substrate. An intaglio plate for reverse printing in which a concave pattern corresponding to the printed image area is formed by etching the film layer is used.

  Further, the pattern transfer unit 23 of the printing apparatus aligns and transfers the ink film pattern on the film sheet 6 onto the substrate 7 to be printed, and then the printed pattern of the transferred ink film is dried and printed. A desired print pattern is formed on the substrate 7. The pattern transfer unit 23 is provided with an alignment table 24 that supports the substrate 7 to be printed from below and has an XYθ mechanism for aligning the position of the substrate 7 to be printed with the film sheet 6. Further, a transfer roller 9 is installed on the film sheet 6, and the transfer roller 9 presses the film sheet 6 against the printing substrate 7 below to transfer the ink film pattern on the film sheet 6 onto the printing substrate 7. To form a print pattern. In addition, an imaging camera 8 for observing the alignment marks of the film sheet 6 and the printing substrate 7 from above is installed. The imaging camera 8 includes a lens having a magnification corresponding to the alignment accuracy and a CCD camera.

  FIG. 3 shows the pattern transfer unit 23, and shows a method of aligning the ink film pattern to be secondarily transferred to the substrate 7 to be printed with the pattern transfer unit 23 with the print pattern of the substrate 7 to be printed. A printing pattern of the reference alignment mark 1 is formed on the substrate 7 to be printed shown in FIG. Then, a pre-dried ink film was formed on the film sheet 6, and the unnecessary pattern portion was removed by the printing plate 22, thereby forming an ink film pattern of the pattern pattern and the alignment mark 2 for alignment. A film sheet 6 is obtained.

  Next, while observing the alignment mark 2 formed on the film sheet 6 and the reference alignment mark 1 which is the printing pattern of the substrate 7 to be printed from the film sheet 6 with the imaging camera 8, the substrate to be printed is aligned by the alignment table 24. The position of the alignment mark 2 is aligned with the center of the reference alignment mark 1 by moving the material 7 in the forward / backward / left / right rotation direction. This alignment can also be performed by an alignment mechanism that moves the film sheet 6, and can also be performed by an alignment mechanism that moves both the film sheet 6 and the substrate to be printed 7. Then, the ink film pattern of the film sheet 6 is printed by rolling and pressing the transfer roller 9 from above the film sheet 6 in the transfer direction 4 while applying pressure to press the film sheet 6 against the printing substrate 7 below. Secondary transfer is performed on the base material 7 to form a print pattern to obtain a printed matter.

  When the reference alignment mark 1 is printed on the substrate 7 to be printed, and the ink film pattern of the reference alignment mark 1 formed on the film sheet 6 is applied to the substrate 7 on which the printing pattern of the reference alignment mark 1 is formed. At the time of transfer, a distorted print pattern as shown in FIG. 1B or 1C is formed on the substrate 7 to be printed. That is, depending on the dry state of the ink film pattern on the film sheet 6, the thickness of the ink film pattern, and the transfer pressure of the transfer roller 9, the ink film pattern is transferred to the substrate 7 to be printed. As shown in the deformation reference alignment mark 3 shown in FIG. 1, the print pattern may be deformed by being pushed out in the transfer direction 4 for a long time. Similarly, when the alignment mark 2 is transferred to the substrate 7 to be printed, a printing pattern having a shape that is pushed out in the transfer direction 4 of the transfer roller 9 as in the modified alignment mark 5 shown in FIG. May be printed.

  For example, the surface of the film sheet 6 on which an ink film pattern of R (red) G (green) B (blue) and a black pattern is formed on a printing substrate 7 for a film color filter is sequentially transferred by a transfer roller 9. The ink film pattern is secondarily transferred from the film sheet 6 to the substrate 7 to be printed by pressing and pressing. When the ink film pattern is transferred to the printing substrate 7 and printed, the dots of the pattern pattern ink on the film sheet 6 are continuous even if they are small. Then, since many dots contact the substrate 7 to be printed at a time, the transfer pressure of the ink film pattern of the pattern pattern to the substrate 7 to be printed is dispersed into many dots. On the other hand, since the ink film pattern of the alignment mark 2 is often arranged at a position away from the position of the pattern pattern, the transfer pressure applied to the ink film pattern of the alignment mark 2 at the time of transfer is determined by the alignment Since it concentrates on the area | region of a small amount of ink of only the mark 2, the alignment mark 2 may deform | transform and may be transcribe | transferred to the to-be-printed base material 7. FIG.

  These measures include ink film thickness, drying management, transfer pressure, speed management, and the like. However, even if these measures are taken, it is not always perfect. Therefore, in the present invention, the transfer roller 9 is pressed when the alignment mark is transferred to the printing substrate 7 by applying pressure with the transfer roller 9 as follows. The transfer pressure is not concentrated on the film sheet 6.

  FIG. 4A shows a plan view of the alignment mark 2 of the film sheet 6 and the reference alignment mark 1 of the print pattern of the substrate 7 to be printed, and FIG. 4B shows a side view thereof. As shown in FIG. 4, the printed pattern of the reference alignment mark 1 is formed, for example, in an annular shape having an outer diameter of 500 μm, and when the field of view of the imaging camera 8 is 1 mm square, which is twice the outer shape, outside the field of the field of view. Then, a printing pattern of the ink bank 10 is formed so as to surround the four sides of the reference alignment mark 1. The reference alignment mark 1 of the printing substrate 7 and the printing pattern of the ink bank 10 are printed by the printing apparatus shown in FIG. In order to form the printing pattern, the printing apparatus forms an ink film pattern by a primary transfer process in which a pattern removing unit removes an unnecessary pre-dried ink film pattern on the film sheet 6 by the printing plate 22. On the printing plate 22, a pre-dried ink other than a portion that becomes a pattern of the ink bank 10 that surrounds the four sides of the reference alignment mark 1 and the diameter of the reference alignment mark 1 and surrounds the four sides of the reference alignment mark 1 is a film sheet. The intaglio for reverse printing removed from 6 is used. That is, the printing plate 22 is formed by etching the resin film layer in a region of the resin film layer formed on the base substrate to form a concave pattern corresponding to the pattern of the reference alignment mark 1 and the ink bank 10. Use the intaglio plate for reverse printing.

  An ink film pattern comprising an ink bank 10 and a reference alignment mark 1 arranged in a shape surrounding the four sides of the reference alignment mark 1 at a location outside the 1 mm field of view of the imaging camera 8 centered on the reference alignment mark 1 is a film sheet. 6 is transferred to the substrate 7 to be printed to obtain a printed matter on which a printing pattern is formed. In the alignment operation in the case of printing the ink film pattern including the alignment mark 2 and the pattern pattern on the substrate 7 on which the printing pattern is formed, the image read by the imaging camera 8 is processed using image processing software. In the image processing, if unnecessary images are mixed in the field of view of the imaging camera 8, it may cause a malfunction. Therefore, a print pattern of the ink bank 10 is provided outside the range of the field of view of 1 mm square. It was.

  By forming the ink bank 10, when transferring the reference alignment mark 1 to the printing substrate 7 and also when transferring the alignment mark 2 to the printing substrate 7, the transfer is performed as follows. It is possible to prevent the pressure from concentrating on the alignment marks and to prevent the imaging camera 8 from capturing the reference alignment mark 1 and the alignment mark 2. First, the ink bank 10 and the reference alignment mark 1 are formed in an ink film pattern on the film sheet 6 by primary transfer processing from the printing plate 22. The surface of the film sheet 6 on which the ink film pattern is formed is pressed by the pattern transfer unit 23 against the substrate 7 to be printed by the transfer roller 9, and the ink film pattern is applied from the film sheet 6 to the substrate 7 to be printed. Secondary transfer. The transfer pressure of the transfer roller 9 at the time of the secondary transfer is dispersed to the reference alignment mark 1 and the ink bank 10, and the ink film pattern of the reference alignment mark 1 is faithful without deformation as shown in FIG. There is an effect that a printing pattern transferred to the printing substrate 7 in a shape is formed. In order to increase this effect, it is desirable that the size of the ink bank 10 be formed to be twice or more the diameter of the reference alignment mark 1.

Next, a new ink liquid film is supplied and installed on a new surface of the film sheet 6 from the coating unit 21 and preliminarily dried to form a preliminarily dried ink film. Then, the printing plate 22 removes unnecessary portions from the pre-dried ink film, whereby an ink film pattern comprising a new picture pattern and an alignment mark 2 having a diameter accommodated in the ring of the annular reference alignment mark 1 is obtained. Formed on a film sheet 6. Next, the alignment mark 2 of the ink film pattern on the film sheet 6 is aligned with the center position of the ring of the reference alignment mark 1 of the printing pattern of the substrate 7 to be printed by the pattern transfer unit 23 of the printing apparatus. Then, the alignment mark 2 and the ink film pattern of the picture pattern are transferred to the substrate 7 to be printed. At that time, the alignment mark 2 of the ink film pattern of the film sheet 6 is in contact with the substrate 7 to be printed, and the surface of the film sheet 6 is in contact with the ink bank 10 of the printing pattern of the substrate 7 to be printed. The transfer pressure is distributed to the alignment mark 2 portion and the ink bank 10 portion. Accordingly, when the alignment mark 2 is transferred, similarly to the transfer of the reference alignment mark 1, the printing substrate 7 on which the ink film pattern of the alignment mark 2 is transferred without deformation and the printing pattern is formed. Is obtained.

  As described above, in the present invention, when an ink film pattern is formed on the soft film sheet 6 and is transferred to the substrate 7 to be printed by being pressed by the transfer roller 9, stress is applied to the film sheet 6. By transferring an ink film pattern having an ink bank 10 together with the reference alignment mark 1 to the substrate 7 to be printed, the problem of distortion and thereby the distortion of the transfer shape of the alignment mark is transferred to the substrate 7 to be printed of the reference alignment mark 1. There is an effect that the transfer pattern is not distorted. Further, the alignment mark 2 is transferred by transferring the alignment mark 2 aligned with the position of the reference alignment mark 1 to the substrate 7 on which the printing pattern of the reference alignment mark 1 and the ink bank 10 is formed. There is a special effect that can prevent the printed pattern from being distorted. This effect solves the problem that the soft film sheet 6 is distorted. For the substrate 7 to be printed, the transfer of the alignment mark is not distorted regardless of whether it is a soft film or a plate. The substrate 7 to be printed is not limited.

  In the present invention, it is desirable that the reference alignment mark 1 has an annular shape and the alignment mark 2 has a circular shape. The reason is that the center position is easy to grasp. For example, the center of the cross and cross alignment marks is easy to grasp, but if flatness occurs during printing, the line becomes thick and thin, making it difficult to grasp the center position.

  On the other hand, in the case of a circular mark, even if some chipping or flatness occurs during transfer, it is easy to find the center position if it can be caught as a circle by using the circle recognition function with image processing software There is an effect that is possible.

  By using such a method to transfer and print an alignment mark faithful to the printing plate 22, it is possible to provide a printing method that enables original highly accurate positioning.

  By using this technology, high accuracy with excellent reproducibility is achieved by using an imaging camera 8 comprising a general alignment table 24 having an XYθ mechanism and a lens having a magnification corresponding to the alignment accuracy, a CCD camera, and the like. An alignment method can be provided.

  Further, in the present invention, if the number of colors to be superimposed on the reference alignment mark 1 and the alignment mark 2 is prepared, innumerable high-precision overprinting is possible.

(A) It is a top view of the alignment mark transcribe | transferred to the to-be-printed base material by embodiment of this invention. (B) It is a top view of an example of the alignment mark transcribe | transferred by the prior art. (C) It is a top view of the other example of the alignment mark transcribe | transferred by the prior art. It is a schematic diagram of a printing apparatus used in an embodiment of the present invention. It is a schematic diagram of the pattern transfer part of the printing apparatus used by this invention. (A) It is a top view of the alignment mark which embodiment of this invention forms. (B) It is a side view of the alignment mark which embodiment of this invention forms.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reference alignment mark 2 ... Alignment mark 3 ... Deformation reference alignment mark 4 ... Transfer direction 5 ... Deformation alignment mark 6 ... Film sheet 7 ... Printed substrate 8 .... Image camera 9 ... Transfer roller 10 ... Ink bank 21 ... Coating part 22 ... Print plate 23 ... Pattern transfer part 24 ... Alignment table

Claims (2)

  A printing plate for use in a printing apparatus that performs reverse printing, a concave pattern corresponding to a pattern of a reference alignment mark, and a pattern of an ink bank that surrounds the four sides of the reference alignment mark and is at least twice the diameter of the reference alignment mark A printing plate, wherein a concave pattern corresponding to is formed.   A step of forming a pre-dried ink film on a film sheet having ink peelability, and then removing unnecessary portions of the pre-dried ink film with a printing plate to enclose the reference alignment mark and its four sides on the film sheet A step of forming an ink film pattern having an ink bank pattern; and pressing the ink film pattern of the film sheet against a substrate to be printed and pressurizing the ink film pattern from the film sheet side with a transfer roller. A printing method comprising a step of transferring to a printing substrate to form a printing pattern.

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